Pasteurizer



Sept. 30, 1930. I I LASSEN 1,777,208

PASTEURIZER Original Filed July 14, 1925 CAD Patented Sept. 30, 1930 STATES PATENT OFFICE FORENEDE BRYGGERIER, OF COPENHAGEN DENMARK A PASTEURIZER Original application filediJ'uly 14, 1925, Serial No. 43,656, and'in Denmark February 19, 1925. Divided and this application filed September 4, 1928. Serial No. 303,922.

This invention relates to an apparatus for pasteurlzmg liquids contaming gases whlch escape on heating and whose presence in the air space thus left in the bottle prevents the complete pasteurization of the contents. It is extremely diflicult to ensure the pasteurization of the gases in the air space. The air space causes the liquid in the bottle to toss during transport, especially during sea transport. This tossing is detrimental to the liquids, especially if they contain absorbed gases. This invention eliminates these drawbacks. According to this invention, the liquid to be pasteurized is heated in expansible containers. The containers are completely, or as completely as practicable, filled with the liquid. The containers and the contained liquid are then heated to the pasteurizing temperature. When the pasteurization is completed, the containers are cooled. The heating of the liquids causes them to expand, thus causing an expansion of the container. On cooling the liquids contract. Usually the containers are so constructed that the partial vacuum resulting from the contraction of the liquids is insufficient to cause the restoration of the original volume of the container. Under such circumstances a small gas space will remain at the top of the'container. It is desirable to remove this air space when the liquid is to be shipped in the container in which it is pasteurized. This removal is desirable because it prevents the tossing of the liquid during shipment and causes the reabsorption of the gases in the air space. Another important consideration is that containers full of liquid are better able to withstand mechanical forces than containers only partially filled. According to a pasteurizing method the containers after cooling are exposed to an external pressure sufficient to restore them to their original volume. The

container is then completely filled with liquid and the liquid contains the same gases as before pasteurization; According to'this invention the containers have an expansible portionbf This is obtained by constructing the container so that a wall portion shall be made of a thinneror softer'meta'l than the rest of the container. Thiswall portion expands when theliquid is heated. It may be restored to its original shape thus restoring the containerto its original volume. This invention may be further understood by reference'to the accompanying drawings wherein; Fig. l is a side elevation ofa pasteurizing plant with part of the tank brolrenaway, showing the containers in place and having the smallest volume. Fig. 2 shows an expansible container having its greatest volume. Fig. 3 is an end elevation of Fig. 1. Fig.4 is a plan top view of Fig. 1.. In the constructional form illustrated in the drawings, the expansible container consists of a metal bottle a, the bottom of which is made of a softer or thinner material than the remainder of the bottle. When the pressure in the interior of the container corresponds to that at the ordinary temperature, the bottom. 72 of the container is concave. Owing to the relative weakness of the bottom, it may bulge (6 Fig. 2) when the interior pressure increases during pasteurization. For example the bottom may be made ofaluminium, the bottle proper being made of hard aluminium and the bottom of softer aluminium. If such bottles be made to hold 25 liters, they can compete economically withcommon beer bottles. They may be produced so cheaply that they need not be returnedto the breweries or other pasteurizing plant. As stated before, a more stable product is obtainable than when containers having a small air space are employed. Many diflerent devices for pasteurizing the liquids in'the above described expansible containers and many diflerent devices for exerting an exterior pressure on the containers after pasteurization may be employed. The pressure may e.-g. be exerted hydraulically. I prefer, however, the embodiment illustrated. This plant consists. of any type of pasteurizing vat'h, provided with means for circulating hot water to obtain the required pasteurizing temperature and means for circulating cold water for cooling purposes. The vat is also provided with communicating compartments in which the containers a are placed. A guide rod d runs down'the center of the vat. The containers are placed in rows on either side of this rod. Each of'the con"- tainers rests on a standard 0. The containers are closed by a capig, provided-with the neo essary packing. A lever e is slidably mounted on the rod d and capable of being'swung to either side of the tank. On this lever is wblbck ,f containinga recess which fits over the caps (,1. When the containers are heated,

the expansion of the liquid forces the bottom from concave to convex position. After the containers are cooled, the lever is brought over the caps. The force exerted by this lever combined with the partial vacuum within the container and the reaction of the standard'forces the bottom inwards, thus restoring the original volume of=the containers.

The above description of my inventionsis not to be taken as limitingbut rather as illustrative of my invention, which, I claim, is:

L In a pasteurizing device, a vat, rows of standards in said vat, rows of containers with e-xpansible bottoms on said-standards, a bar intermediate said rows, a slidable lever on saidfbar, by means of' which lever the. containers after the heating and the subsequent cooling may be subjected'to an external pressure.

2. In a device for pasteurizing liquids containingdissolved gases which are partially liberated during the pasteurization but subsequently, re-dissolved, a metallic sterilizing vessel havingthe bottom wall portionmade of softer material than the rest of the vessel, thereby permitting said wall to bulge out during heating and to regain its original shape after cooling.

3. In a device for pasteuring liquids containing dissolved gases which are partially liberated during the pasteurization but subsequent-ly re-dissolved, ametallic sterilizing vessel having the bottom wall portion made of thinner material than the rest of the vessel, thereby permitting saidwall to bulge out during heating and to regain its original shape after cooling.

4. In a device for pasteurizing liquids containing'dissolved ases. which are partially liberated during the pasteurization but subsequently r'e-dissolved, a sterilizing vessel made of hard'material and having a bottom wall portionof soft material which allows the alteration of the volume of the, container, 7 pp adevice for'pasteurizingliquids contaming dissolved gases which are partially liberated during the pasteurization butf subsequently redissolved, a sterilizing vessel FREDERIK LASSEN. 

